We continue to develop resources related to the COVID-19 pandemic. See COVID-19 initiatives on Appropedia for more information.
Many sustainability wikis exist, intending to provide a place of collaboration on green knowledge. See green wikis for an overview of active wikis for knowledge sharing and collaboration in sustainability.
Of those collaborative sites calling themselves a Sustainability Wiki, by far the most active and largest is Appropedia, covering sustainable technologies and green living practices. (Browse Appropedia.)